This invention relates to air heating devices and in particular to a new and improved forced air heater.
Typical heated air sources use a gas burner in a combustion chamber for producing heated air, and a blower to move the heated air to the area to be heated. Heating apparatus of this type has been widely used and is very satisfactory in many installations. However these systems also have certain disadvantages. Substantial amounts of air must be moved through the combustion chamber in order to accomplish this, and the blower usually is exposed to the heated air. Also, arrangements of this type do not always make the most efficient use of the energy source.
One use for forced air heat is in the provision of warm air curtains which are used at open doorways and at windows in retail and commercial structures as well as residences. These types of systems are typically installed at the ceiling where space limitations are severe and where the heat of the burner chamber creates problems with adjacent structures and components.
One of the objects of the present invention is to provide a new and improved heated air system wherein the blower or other power source for moving the air can be isolated from the heat source thereby reducing the overall volume of the hot air portion of the system and also reducing the exposure of the blower to hot air.
Another object is to provide such an air heating system having a relatively large volume air supply duct and a blower which moves air therethrough, and a relatively small volume combustion chamber for producing heated air, with the heated air being drawn from the combustion chamber into the main air duct by the moving stream of air in the main air duct. With such an arrangement, a single blower operating with ambient temperature air provides the entire force for moving warm air to the desired location, while permitting a high efficiency, high temperature burner chamber operation.
It is another object of the invention to provide a high efficiency burner chamber consisting essentially of refractory material with an apertured downstream wall of refractory material so that essentially complete combustion is obtained with substantially no unburned fuel in the heated air.
These and other objects, advantages, features and results will more fully appear in the course of the following description.